Friday, July 17, 2015

Although
this cluster of stars gained its name due to its five brightest stars,
it is home to hundreds more. The huge number of massive young stars in
the cluster is clearly captured in this NASA/ESA Hubble Space Telescope
image.

The cluster is located close to the Arches Cluster
and is just 100 light-years from the centre of our galaxy. The
cluster’s proximity to the dust at the centre of the galaxy means that
much of its visible light is blocked, which helped to keep the cluster
unknown until its discovery in 1990, when it was revealed by
observations in the infrared. Infrared images of the cluster, like the
one shown here, allow us to see through the obscuring dust to the hot
stars in the cluster.

The Quintuplet Cluster hosts two extremely rare luminous blue variable stars: the Pistol Star
and the lesser known V4650 Sgr. If you were to draw a line horizontally
through the centre of this image from left to right, you could see the
Pistol Star hovering just above the line about one third of the way
along it. The Pistol Star is one of the most luminous known stars in the
Milky Way and takes its name from the shape of the Pistol Nebula
that it illuminates, but which is not visible in this infrared image.
The exact age and future of the Pistol Star are uncertain, but it is
expected to end in a supernova or even a hypernova in one to three million years.

The cluster also contains a number of red supergiants.
These stars are among the largest in the galaxy and are burning their
fuel at an incredible speed, meaning they will have a very short
lifetime. Their presence suggests an average cluster age of nearly four
million years. At the moment these stars are on the verge of exploding
as supernovae. During their spectacular deaths they will release vast
amounts of energy which, in turn, will heat the material — dust and gas —
between the other stars.

This observation shows the Quintuplet Cluster in the infrared and demonstrates the leap in Hubble’s performance since its 1999 image of same object.